Currently available computer output printers are normally provided with one type of document feeding and guide means for advancing a document of the continuous web type through the printing station or a different type of document feeding and guiding means for advancing individual cut form type documents through the printing station. The ability to print only a document of the continuous web type or individual cut form type documents thus limits the versatility and use of the particular printer to only a single mode of operation. Certain presently available printers may be used to feed either a document of the continuous web type or individual cut form type documents but require that the operator make certain adjustments of the pin or spur drive wheels used to drive the document of the continuous web type and/or require adjustment of the friction rolls used to drive the cut form type documents. In printers in which the continuous web type documents and the cut form documents follow the same feed path into the printer, the continuous web type document must be completely removed before the printer can be adapted for use in printing individual cut form documents, such as precut sheets, including letterhead stationery and the like or envelopes, and this required removal of the continuous web type document is time consuming and bother-some to the operator.
U.S. Pat. No. 4,417,825 discloses a document driving and guide arrangement for high-speed printers which includes both pin wheel driving means and friction roll drive means for alternately advancing either a continuous web type document or individual cut form documents through the printing station of the printer. The document feeding arrangement of this patent includes a shifting lever which must be actuated by the operator to selectively feed either the continuous web type document or individual cut form documents. The switching of the lever by the operator changes the document driving mechanism so that it operates in either a friction drive mode or a spur or pin wheel drive mode. The drive mode shifting lever and the associated mechanism adds to the cost of producing the printer and also complicates the operation of the printer. In either drive mode, the two different types of documents follow the same path of travel into the printer so that the continuous web type document must be removed before the individual cut form documents can be fed to the printer.
U.S. Pat. No. 4,164,376 discloses a printer including a multiple path paper feed system which permits the feeding of a continuous web type document from the front, bottom or rear of the printer housing. The optional paper or document feed paths are provided to permit installation of the printer and location of the document supply source in a position that is most comfortable and convenient for placement of the printer and for operator placement. However, the document feeding means of this printer is disclosed as being of the pin or spur wheel type adapted to feed only continuous web type documents having uniformly spaced perforations along its outer edges. The feed means of this printer is positioned downstream of the printer head and platen so that this printer is not adaptable for feeding individual cut form documents.
Currently available output printers have the head supported for back and forth transverse movement in a horizontal plane with the platen supported in a vertical plane and this arrangement tends to increase the overall height of the printer, and to prevent the manual feeding of relatively short cut form documents, such as envelopes, into the printer. The nip of the document feed rolls is usually located a distance of one or more inches downstream of the print line so that the first and last lines of print on cut form documents must be spaced corresponding distances from the respective leading and trailing edges of the document.